1 /*
2 * Copyright (c) 2018, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotCacheAccess.hpp"
27 #include "cds/aotClassInitializer.hpp"
28 #include "cds/aotClassLocation.hpp"
29 #include "cds/aotConstantPoolResolver.hpp"
30 #include "cds/aotLogging.hpp"
31 #include "cds/aotMappedHeapLoader.hpp"
32 #include "cds/aotMappedHeapWriter.hpp"
33 #include "cds/aotMetaspace.hpp"
34 #include "cds/aotOopChecker.hpp"
35 #include "cds/aotReferenceObjSupport.hpp"
36 #include "cds/aotStreamedHeapLoader.hpp"
37 #include "cds/aotStreamedHeapWriter.hpp"
38 #include "cds/archiveBuilder.hpp"
39 #include "cds/archiveUtils.hpp"
40 #include "cds/cds_globals.hpp"
41 #include "cds/cdsConfig.hpp"
42 #include "cds/cdsEnumKlass.hpp"
43 #include "cds/cdsHeapVerifier.hpp"
44 #include "cds/heapShared.inline.hpp"
45 #include "cds/regeneratedClasses.hpp"
46 #include "classfile/classLoaderData.hpp"
47 #include "classfile/javaClasses.inline.hpp"
48 #include "classfile/modules.hpp"
49 #include "classfile/stringTable.hpp"
50 #include "classfile/symbolTable.hpp"
51 #include "classfile/systemDictionary.hpp"
52 #include "classfile/systemDictionaryShared.hpp"
53 #include "classfile/vmClasses.hpp"
54 #include "classfile/vmSymbols.hpp"
55 #include "code/aotCodeCache.hpp"
56 #include "gc/shared/collectedHeap.hpp"
57 #include "gc/shared/gcLocker.hpp"
58 #include "gc/shared/gcVMOperations.hpp"
59 #include "logging/log.hpp"
60 #include "logging/logStream.hpp"
61 #include "memory/iterator.inline.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "oops/compressedOops.inline.hpp"
65 #include "oops/fieldStreams.inline.hpp"
66 #include "oops/objArrayOop.inline.hpp"
67 #include "oops/oop.inline.hpp"
68 #include "oops/oopHandle.inline.hpp"
69 #include "oops/typeArrayOop.inline.hpp"
70 #include "prims/jvmtiExport.hpp"
71 #include "runtime/arguments.hpp"
72 #include "runtime/fieldDescriptor.inline.hpp"
73 #include "runtime/globals_extension.hpp"
74 #include "runtime/init.hpp"
75 #include "runtime/javaCalls.hpp"
76 #include "runtime/mutexLocker.hpp"
77 #include "runtime/safepointVerifiers.hpp"
78 #include "utilities/bitMap.inline.hpp"
79 #include "utilities/copy.hpp"
80 #if INCLUDE_G1GC
81 #include "gc/g1/g1CollectedHeap.hpp"
82 #endif
83
84 #if INCLUDE_CDS_JAVA_HEAP
85
86 struct ArchivableStaticFieldInfo {
87 const char* klass_name;
88 const char* field_name;
89 InstanceKlass* klass;
90 int offset;
91 BasicType type;
92
93 ArchivableStaticFieldInfo(const char* k, const char* f)
94 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
95
96 bool valid() {
97 return klass_name != nullptr;
98 }
99 };
100
101 class HeapShared::ContextMark : public StackObj {
102 ResourceMark rm;
103 public:
104 ContextMark(const char* c) : rm{} {
105 _context->push(c);
106 }
107 ~ContextMark() {
108 _context->pop();
109 }
110 };
111
112 // Anything that goes in the header must be thoroughly purged from uninitialized memory
113 // as it will be written to disk. Therefore, the constructors memset the memory to 0.
114 // This is not the prettiest thing, but we need to know every byte is initialized,
115 // including potential padding between fields.
116
117 ArchiveMappedHeapHeader::ArchiveMappedHeapHeader(size_t ptrmap_start_pos,
118 size_t oopmap_start_pos,
119 HeapRootSegments root_segments) {
120 memset((char*)this, 0, sizeof(*this));
121 _ptrmap_start_pos = ptrmap_start_pos;
122 _oopmap_start_pos = oopmap_start_pos;
123 _root_segments = root_segments;
124 }
125
126 ArchiveMappedHeapHeader::ArchiveMappedHeapHeader() {
127 memset((char*)this, 0, sizeof(*this));
128 }
129
130 ArchiveMappedHeapHeader ArchiveMappedHeapInfo::create_header() {
131 return ArchiveMappedHeapHeader{_ptrmap_start_pos,
132 _oopmap_start_pos,
133 _root_segments};
134 }
135
136 ArchiveStreamedHeapHeader::ArchiveStreamedHeapHeader(size_t forwarding_offset,
137 size_t roots_offset,
138 size_t num_roots,
139 size_t root_highest_object_index_table_offset,
140 size_t num_archived_objects) {
141 memset((char*)this, 0, sizeof(*this));
142 _forwarding_offset = forwarding_offset;
143 _roots_offset = roots_offset;
144 _num_roots = num_roots;
145 _root_highest_object_index_table_offset = root_highest_object_index_table_offset;
146 _num_archived_objects = num_archived_objects;
147 }
148
149 ArchiveStreamedHeapHeader::ArchiveStreamedHeapHeader() {
150 memset((char*)this, 0, sizeof(*this));
151 }
152
153 ArchiveStreamedHeapHeader ArchiveStreamedHeapInfo::create_header() {
154 return ArchiveStreamedHeapHeader{_forwarding_offset,
155 _roots_offset,
156 _num_roots,
157 _root_highest_object_index_table_offset,
158 _num_archived_objects};
159 }
160
161 HeapArchiveMode HeapShared::_heap_load_mode = HeapArchiveMode::_uninitialized;
162 HeapArchiveMode HeapShared::_heap_write_mode = HeapArchiveMode::_uninitialized;
163
164 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
165 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
166 size_t HeapShared::_total_obj_count;
167 size_t HeapShared::_total_obj_size;
168
169 #ifndef PRODUCT
170 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
171 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
172 static const char* _test_class_name = nullptr;
173 static Klass* _test_class = nullptr;
174 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
175 #endif
176
177
178 //
179 // If you add new entries to the following tables, you should know what you're doing!
180 //
181
182 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
183 {"java/lang/Integer$IntegerCache", "archivedCache"},
184 {"java/lang/Long$LongCache", "archivedCache"},
185 {"java/lang/Byte$ByteCache", "archivedCache"},
186 {"java/lang/Short$ShortCache", "archivedCache"},
187 {"java/lang/Character$CharacterCache", "archivedCache"},
188 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
189 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
190 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
191 {"java/util/ImmutableCollections", "archivedObjects"},
192 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
193 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
194 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
195 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
196
197 #ifndef PRODUCT
198 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
199 #endif
200 {nullptr, nullptr},
201 };
202
203 // full module graph
204 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
205 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
206 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
207 {"java/lang/Module$ArchivedData", "archivedData"},
208 {nullptr, nullptr},
209 };
210
211 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
212 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
213 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
214 GrowableArrayCHeap<const char*, mtClassShared>* HeapShared::_context = nullptr;
215 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
216 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
217
218 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
219 for (int i = 0; fields[i].valid(); i++) {
220 if (fields[i].klass == ik) {
221 return true;
222 }
223 }
224 return false;
225 }
226
227 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
228 assert(CDSConfig::is_dumping_heap(), "dump-time only");
229 if (CDSConfig::is_dumping_klass_subgraphs()) {
230 // Legacy CDS archive support (to be deprecated)
231 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
232 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
233 } else {
234 return false;
235 }
236 }
237
238 oop HeapShared::CachedOopInfo::orig_referrer() const {
239 return _orig_referrer.resolve();
240 }
241
242 unsigned HeapShared::oop_hash(oop const& p) {
243 assert(SafepointSynchronize::is_at_safepoint() ||
244 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
245 // Do not call p->identity_hash() as that will update the
246 // object header.
247 return primitive_hash(cast_from_oop<intptr_t>(p));
248 }
249
250 // About the hashcode in the cached objects:
251 // - If a source object has a hashcode, it must be copied into the cache.
252 // That's because some cached hashtables are laid out using this hashcode.
253 // - If a source object doesn't have a hashcode, we avoid computing it while
254 // copying the objects into the cache. This will allow the hashcode to be
255 // dynamically and randomly computed in each production, which generally
256 // desirable to make the hashcodes more random between runs.
257 unsigned HeapShared::archived_object_cache_hash(OopHandle const& oh) {
258 oop o = oh.resolve();
259 if (_use_identity_hash_for_archived_object_cache) {
260 // This is called after all objects are copied. It's OK to update
261 // the object's hashcode.
262 //
263 // This may be called after we have left the AOT dumping safepoint.
264 // Objects in archived_object_cache() may be moved by the GC, so we
265 // can't use the address of o for computing the hash.
266 if (o == nullptr) {
267 return 0;
268 } else {
269 return o->identity_hash();
270 }
271 } else {
272 // This is called while we are copying the objects. Don't call o->identity_hash()
273 // as that will update the object header.
274 return oop_hash(o);
275 }
276 }
277
278 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
279 return a.resolve() == b.resolve();
280 }
281
282 static void reset_states(oop obj, TRAPS) {
283 Handle h_obj(THREAD, obj);
284 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
285 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
286 Symbol* method_sig = vmSymbols::void_method_signature();
287
288 while (klass != nullptr) {
289 Method* method = klass->find_method(method_name, method_sig);
290 if (method != nullptr) {
291 assert(method->is_private(), "must be");
292 if (log_is_enabled(Debug, aot)) {
293 ResourceMark rm(THREAD);
294 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
295 }
296 JavaValue result(T_VOID);
297 JavaCalls::call_special(&result, h_obj, klass,
298 method_name, method_sig, CHECK);
299 }
300 klass = klass->super();
301 }
302 }
303
304 void HeapShared::reset_archived_object_states(TRAPS) {
305 assert(CDSConfig::is_dumping_heap(), "dump-time only");
306 log_debug(aot)("Resetting platform loader");
307 reset_states(SystemDictionary::java_platform_loader(), CHECK);
308 log_debug(aot)("Resetting system loader");
309 reset_states(SystemDictionary::java_system_loader(), CHECK);
310
311 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
312 // directly used for class loading, but rather is used by the core library
313 // to keep track of resources, etc, loaded by the null class loader.
314 //
315 // Note, this object is non-null, and is not the same as
316 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
317 // which is null.
318 log_debug(aot)("Resetting boot loader");
319 JavaValue result(T_OBJECT);
320 JavaCalls::call_static(&result,
321 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
322 vmSymbols::bootLoader_name(),
323 vmSymbols::void_BuiltinClassLoader_signature(),
324 CHECK);
325 Handle boot_loader(THREAD, result.get_oop());
326 reset_states(boot_loader(), CHECK);
327 }
328
329 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
330 bool HeapShared::_use_identity_hash_for_archived_object_cache = false;
331
332 bool HeapShared::is_archived_heap_in_use() {
333 if (HeapShared::is_loading()) {
334 if (HeapShared::is_loading_streaming_mode()) {
335 return AOTStreamedHeapLoader::is_in_use();
336 } else {
337 return AOTMappedHeapLoader::is_in_use();
338 }
339 }
340
341 return false;
342 }
343
344 bool HeapShared::can_use_archived_heap() {
345 FileMapInfo* static_mapinfo = FileMapInfo::current_info();
346 if (static_mapinfo == nullptr) {
347 return false;
348 }
349 if (!static_mapinfo->has_heap_region()) {
350 return false;
351 }
352 if (!static_mapinfo->object_streaming_mode() &&
353 !Universe::heap()->can_load_archived_objects() &&
354 !UseG1GC) {
355 // Incompatible object format
356 return false;
357 }
358
359 return true;
360 }
361
362 bool HeapShared::is_too_large_to_archive(size_t size) {
363 if (HeapShared::is_writing_streaming_mode()) {
364 return false;
365 } else {
366 return AOTMappedHeapWriter::is_too_large_to_archive(size);
367 }
368 }
369
370 bool HeapShared::is_too_large_to_archive(oop obj) {
371 if (HeapShared::is_writing_streaming_mode()) {
372 return false;
373 } else {
374 return AOTMappedHeapWriter::is_too_large_to_archive(obj);
375 }
376 }
377
378 bool HeapShared::is_string_too_large_to_archive(oop string) {
379 typeArrayOop value = java_lang_String::value_no_keepalive(string);
380 return is_too_large_to_archive(value);
381 }
382
383 void HeapShared::initialize_loading_mode(HeapArchiveMode mode) {
384 assert(_heap_load_mode == HeapArchiveMode::_uninitialized, "already set?");
385 assert(mode != HeapArchiveMode::_uninitialized, "sanity");
386 _heap_load_mode = mode;
387 };
388
389 void HeapShared::initialize_writing_mode() {
390 assert(!FLAG_IS_ERGO(AOTStreamableObjects), "Should not have been ergonomically set yet");
391
392 if (!CDSConfig::is_dumping_archive()) {
393 // We use FLAG_IS_CMDLINE below because we are specifically looking to warn
394 // a user that explicitly sets the flag on the command line for a JVM that is
395 // not dumping an archive.
396 if (FLAG_IS_CMDLINE(AOTStreamableObjects)) {
397 log_warning(cds)("-XX:%cAOTStreamableObjects was specified, "
398 "AOTStreamableObjects is only used for writing "
399 "the AOT cache.",
400 AOTStreamableObjects ? '+' : '-');
401 }
402 }
403
404 // The below checks use !FLAG_IS_DEFAULT instead of FLAG_IS_CMDLINE
405 // because the one step AOT cache creation transfers the AOTStreamableObjects
406 // flag value from the training JVM to the assembly JVM using an environment
407 // variable that sets the flag as ERGO in the assembly JVM.
408 if (FLAG_IS_DEFAULT(AOTStreamableObjects)) {
409 // By default, the value of AOTStreamableObjects should match !UseCompressedOops.
410 FLAG_SET_DEFAULT(AOTStreamableObjects, !UseCompressedOops);
411 } else if (!AOTStreamableObjects && UseZGC) {
412 // Never write mapped heap with ZGC
413 if (CDSConfig::is_dumping_archive()) {
414 log_warning(cds)("Heap archiving without streaming not supported for -XX:+UseZGC");
415 }
416 FLAG_SET_ERGO(AOTStreamableObjects, true);
417 }
418
419 if (CDSConfig::is_dumping_archive()) {
420 // Select default mode
421 assert(_heap_write_mode == HeapArchiveMode::_uninitialized, "already initialized?");
422 _heap_write_mode = AOTStreamableObjects ? HeapArchiveMode::_streaming : HeapArchiveMode::_mapping;
423 }
424 }
425
426 void HeapShared::initialize_streaming() {
427 assert(is_loading_streaming_mode(), "shouldn't call this");
428 if (can_use_archived_heap()) {
429 AOTStreamedHeapLoader::initialize();
430 }
431 }
432
433 void HeapShared::enable_gc() {
434 if (AOTStreamedHeapLoader::is_in_use()) {
435 AOTStreamedHeapLoader::enable_gc();
436 }
437 }
438
439 void HeapShared::materialize_thread_object() {
440 if (AOTStreamedHeapLoader::is_in_use()) {
441 AOTStreamedHeapLoader::materialize_thread_object();
442 }
443 }
444
445 void HeapShared::archive_interned_string(oop string) {
446 assert(HeapShared::is_writing_mapping_mode(), "Only used by this mode");
447 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, string);
448 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
449 }
450
451 void HeapShared::finalize_initialization(FileMapInfo* static_mapinfo) {
452 if (HeapShared::is_loading()) {
453 if (HeapShared::is_loading_streaming_mode()) {
454 // Heap initialization can be done only after vtables are initialized by ReadClosure.
455 AOTStreamedHeapLoader::finish_initialization(static_mapinfo);
456 } else {
457 // Finish up archived heap initialization. These must be
458 // done after ReadClosure.
459 AOTMappedHeapLoader::finish_initialization(static_mapinfo);
460 }
461 }
462 }
463
464 void HeapShared::make_archived_object_cache_gc_safe() {
465 ArchivedObjectCache* new_cache = new (mtClass)ArchivedObjectCache(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
466
467 // It's safe to change the behavior of the hash function now, because iterate_all()
468 // doesn't call the hash function.
469 _use_identity_hash_for_archived_object_cache = true;
470
471 // Copy all CachedOopInfo into a new table using a different hashing algorithm
472 archived_object_cache()->iterate_all([&] (OopHandle oh, CachedOopInfo info) {
473 new_cache->put_when_absent(oh, info);
474 });
475
476 destroy_archived_object_cache();
477 _archived_object_cache = new_cache;
478 }
479
480 HeapShared::CachedOopInfo* HeapShared::get_cached_oop_info(oop obj) {
481 OopHandle oh(Universe::vm_global(), obj);
482 CachedOopInfo* result = _archived_object_cache->get(oh);
483 oh.release(Universe::vm_global());
484 return result;
485 }
486
487 bool HeapShared::has_been_archived(oop obj) {
488 assert(CDSConfig::is_dumping_heap(), "dump-time only");
489 return get_cached_oop_info(obj) != nullptr;
490 }
491
492 int HeapShared::append_root(oop obj) {
493 assert(SafepointSynchronize::is_at_safepoint(), "sanity");
494 assert(CDSConfig::is_dumping_heap(), "dump-time only");
495 assert(_pending_roots != nullptr, "sanity");
496
497 if (obj == nullptr) {
498 assert(_pending_roots->at(0) == nullptr, "root index 1 is always null");
499 return 0;
500 } else if (CDSConfig::is_dumping_aot_linked_classes()) {
501 // The AOT compiler may refer the same obj many times, so we
502 // should use the same index for this oop to avoid excessive entries
503 // in the roots array.
504 CachedOopInfo* obj_info = get_cached_oop_info(obj);
505 assert(obj_info != nullptr, "must be archived");
506
507 if (obj_info->root_index() > 0) {
508 return obj_info->root_index();
509 } else {
510 int i = _pending_roots->append(obj);
511 obj_info->set_root_index(i);
512 return i;
513 }
514 } else {
515 return _pending_roots->append(obj);
516 }
517 }
518
519 int HeapShared::get_root_index(oop obj) {
520 if (!CDSConfig::is_dumping_heap()) {
521 return -1; // Called by the Leyden old workflow
522 }
523
524 if (java_lang_Class::is_instance(obj)) {
525 obj = scratch_java_mirror(obj);
526 }
527
528 CachedOopInfo* obj_info = get_cached_oop_info(obj);
529 const char* error = nullptr;
530 if (obj_info == nullptr) {
531 error = "Not a cached oop";
532 } else if (obj_info->root_index() < 0) {
533 error = "Not a cached oop root";
534 } else {
535 return obj_info->root_index();
536 }
537
538 ResourceMark rm;
539 log_debug(aot, codecache, oops)("%s: " INTPTR_FORMAT " (%s)", error,
540 cast_from_oop<uintptr_t>(obj),
541 obj->klass()->external_name());
542 return -1;
543 }
544
545 oop HeapShared::get_root(int index, bool clear) {
546 assert(index >= 0, "sanity");
547 assert(is_archived_heap_in_use(), "getting roots into heap that is not used");
548
549 oop result;
550 if (HeapShared::is_loading_streaming_mode()) {
551 result = AOTStreamedHeapLoader::get_root(index);
552 } else {
553 assert(HeapShared::is_loading_mapping_mode(), "must be");
554 result = AOTMappedHeapLoader::get_root(index);
555 }
556
557 if (clear) {
558 clear_root(index);
559 }
560
561 return result;
562 }
563
564 void HeapShared::finish_materialize_objects() {
565 if (AOTStreamedHeapLoader::is_in_use()) {
566 AOTStreamedHeapLoader::finish_materialize_objects();
567 }
568 }
569
570 void HeapShared::clear_root(int index) {
571 if (CDSConfig::is_using_aot_linked_classes()) {
572 // When AOT linked classes are in use, all roots will be in use all
573 // the time, there's no benefit for clearing the roots. Also, we
574 // can't clear the roots as they can be shared.
575 return;
576 }
577
578 assert(index >= 0, "sanity");
579 assert(CDSConfig::is_using_archive(), "must be");
580 if (is_archived_heap_in_use()) {
581 if (log_is_enabled(Debug, aot, heap)) {
582 log_debug(aot, heap)("Clearing root %d: was %zu", index, p2i(get_root(index, false /* clear */)));
583 }
584 if (HeapShared::is_loading_streaming_mode()) {
585 AOTStreamedHeapLoader::clear_root(index);
586 } else {
587 assert(HeapShared::is_loading_mapping_mode(), "must be");
588 AOTMappedHeapLoader::clear_root(index);
589 }
590 }
591 }
592
593 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
594 assert(CDSConfig::is_dumping_heap(), "dump-time only");
595
596 assert(!obj->is_stackChunk(), "do not archive stack chunks");
597 if (has_been_archived(obj)) {
598 return true;
599 }
600
601 if (is_too_large_to_archive(obj)) {
602 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
603 p2i(obj), obj->size());
604 debug_trace();
605 return false;
606 }
607
608 AOTOopChecker::check(obj); // Make sure contents of this oop are safe.
609 count_allocation(obj->size());
610
611 if (HeapShared::is_writing_streaming_mode()) {
612 AOTStreamedHeapWriter::add_source_obj(obj);
613 } else {
614 AOTMappedHeapWriter::add_source_obj(obj);
615 }
616
617 OopHandle oh(Universe::vm_global(), obj);
618 CachedOopInfo info = make_cached_oop_info(obj, referrer);
619 archived_object_cache()->put_when_absent(oh, info);
620 archived_object_cache()->maybe_grow();
621
622 Klass* k = obj->klass();
623 if (k->is_instance_klass()) {
624 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
625 // This ensures that during the production run, whenever Java code sees a cached object
626 // of type X, we know that X is already initialized. (see TODO comment below ...)
627
628 if (InstanceKlass::cast(k)->is_enum_subclass()
629 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
630 // we must store them as AOT-initialized.
631 || (subgraph_info == _dump_time_special_subgraph))
632 // TODO: we do this only for the special subgraph for now. Extending this to
633 // other subgraphs would require more refactoring of the core library (such as
634 // move some initialization logic into runtimeSetup()).
635 //
636 // For the other subgraphs, we have a weaker mechanism to ensure that
637 // all classes in a subgraph are initialized before the subgraph is programmatically
638 // returned from jdk.internal.misc.CDS::initializeFromArchive().
639 // See HeapShared::initialize_from_archived_subgraph().
640 {
641 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
642 }
643
644 if (java_lang_Class::is_instance(obj)) {
645 Klass* mirror_k = java_lang_Class::as_Klass(obj);
646 if (mirror_k != nullptr) {
647 AOTArtifactFinder::add_cached_class(mirror_k);
648 }
649 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
650 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
651 if (m != nullptr) {
652 if (RegeneratedClasses::has_been_regenerated(m)) {
653 m = RegeneratedClasses::get_regenerated_object(m);
654 }
655 InstanceKlass* method_holder = m->method_holder();
656 AOTArtifactFinder::add_cached_class(method_holder);
657 }
658 } else if (AOTCodeCache::is_dumping_code() &&
659 (java_lang_invoke_MethodHandle::is_instance(obj) || is_interned_string(obj))) {
660 // Needed by AOT compiler.
661 append_root(obj);
662 }
663 }
664
665 if (log_is_enabled(Debug, aot, heap)) {
666 ResourceMark rm;
667 LogTarget(Debug, aot, heap) log;
668 LogStream out(log);
669 out.print("Archived heap object " PTR_FORMAT " : %s ",
670 p2i(obj), obj->klass()->external_name());
671 if (java_lang_Class::is_instance(obj)) {
672 Klass* k = java_lang_Class::as_Klass(obj);
673 if (k != nullptr) {
674 out.print("%s", k->external_name());
675 } else {
676 out.print("primitive");
677 }
678 }
679 out.cr();
680 }
681
682 return true;
683 }
684
685 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
686 36137, // prime number
687 AnyObj::C_HEAP,
688 mtClassShared> {
689 public:
690 oop get_oop(MetaspaceObj* ptr) {
691 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
692 OopHandle* handle = get(ptr);
693 if (handle != nullptr) {
694 return handle->resolve();
695 } else {
696 return nullptr;
697 }
698 }
699 void set_oop(MetaspaceObj* ptr, oop o) {
700 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
701 OopHandle handle(Universe::vm_global(), o);
702 put_when_absent(ptr, handle);
703 }
704 void remove_oop(MetaspaceObj* ptr) {
705 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
706 OopHandle* handle = get(ptr);
707 if (handle != nullptr) {
708 handle->release(Universe::vm_global());
709 remove(ptr);
710 }
711 }
712 };
713
714 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
715 if (CDSConfig::is_dumping_preimage_static_archive() && scratch_resolved_references(src) != nullptr) {
716 // We are in AOT training run. The class has been redefined and we are giving it a new resolved_reference.
717 // Ignore it, as this class will be excluded from the AOT config.
718 return;
719 }
720 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
721 _scratch_objects_table->set_oop(src, dest);
722 }
723 }
724
725 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
726 return (objArrayOop)_scratch_objects_table->get_oop(src);
727 }
728
729 void HeapShared::init_dumping() {
730 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
731 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
732 _pending_roots->append(nullptr); // root index 0 represents a null oop
733 }
734
735 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
736 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
737 BasicType bt = (BasicType)i;
738 if (!is_reference_type(bt)) {
739 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
740 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
741 }
742 }
743 }
744
745 // Given java_mirror that represents a (primitive or reference) type T,
746 // return the "scratch" version that represents the same type T. Note
747 // that java_mirror will be returned if the mirror is already a scratch mirror.
748 //
749 // See java_lang_Class::create_scratch_mirror() for more info.
750 oop HeapShared::scratch_java_mirror(oop java_mirror) {
751 assert(java_lang_Class::is_instance(java_mirror), "must be");
752
753 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
754 BasicType bt = (BasicType)i;
755 if (!is_reference_type(bt)) {
756 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
757 return java_mirror;
758 }
759 }
760 }
761
762 if (java_lang_Class::is_primitive(java_mirror)) {
763 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
764 } else {
765 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
766 }
767 }
768
769 oop HeapShared::scratch_java_mirror(BasicType t) {
770 assert((uint)t < T_VOID+1, "range check");
771 assert(!is_reference_type(t), "sanity");
772 return _scratch_basic_type_mirrors[t].resolve();
773 }
774
775 oop HeapShared::scratch_java_mirror(Klass* k) {
776 return _scratch_objects_table->get_oop(k);
777 }
778
779 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
780 _scratch_objects_table->set_oop(k, mirror);
781 }
782
783 void HeapShared::remove_scratch_objects(Klass* k) {
784 // Klass is being deallocated. Java mirror can still be alive, and it should not
785 // point to dead klass. We need to break the link from mirror to the Klass.
786 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
787 oop mirror = _scratch_objects_table->get_oop(k);
788 if (mirror != nullptr) {
789 java_lang_Class::set_klass(mirror, nullptr);
790 }
791 _scratch_objects_table->remove_oop(k);
792 if (k->is_instance_klass()) {
793 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
794 }
795 }
796
797 //TODO: we eventually want a more direct test for these kinds of things.
798 //For example the JVM could record some bit of context from the creation
799 //of the klass, such as who called the hidden class factory. Using
800 //string compares on names is fragile and will break as soon as somebody
801 //changes the names in the JDK code. See discussion in JDK-8342481 for
802 //related ideas about marking AOT-related classes.
803 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
804 return ik->is_hidden() &&
805 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
806 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
807 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
808 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
809 }
810
811 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
812 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
813 }
814
815 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
816 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
817 }
818
819 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
820 return CDSConfig::is_dumping_method_handles() &&
821 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
822 }
823
824
825 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
826 ik->set_has_aot_initialized_mirror();
827
828 oop orig_mirror;
829 if (RegeneratedClasses::is_regenerated_object(ik)) {
830 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
831 precond(orig_ik->is_initialized());
832 orig_mirror = orig_ik->java_mirror();
833 } else {
834 precond(ik->is_initialized());
835 orig_mirror = ik->java_mirror();
836 }
837
838 oop m = scratch_java_mirror(ik);
839 int nfields = 0;
840 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
841 if (fs.access_flags().is_static()) {
842 fieldDescriptor& fd = fs.field_descriptor();
843 int offset = fd.offset();
844 switch (fd.field_type()) {
845 case T_OBJECT:
846 case T_ARRAY:
847 {
848 oop field_obj = orig_mirror->obj_field(offset);
849 m->obj_field_put(offset, field_obj);
850 if (field_obj != nullptr) {
851 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
852 assert(success, "sanity");
853 }
854 }
855 break;
856 case T_BOOLEAN:
857 m->bool_field_put(offset, orig_mirror->bool_field(offset));
858 break;
859 case T_BYTE:
860 m->byte_field_put(offset, orig_mirror->byte_field(offset));
861 break;
862 case T_SHORT:
863 m->short_field_put(offset, orig_mirror->short_field(offset));
864 break;
865 case T_CHAR:
866 m->char_field_put(offset, orig_mirror->char_field(offset));
867 break;
868 case T_INT:
869 m->int_field_put(offset, orig_mirror->int_field(offset));
870 break;
871 case T_LONG:
872 m->long_field_put(offset, orig_mirror->long_field(offset));
873 break;
874 case T_FLOAT:
875 m->float_field_put(offset, orig_mirror->float_field(offset));
876 break;
877 case T_DOUBLE:
878 m->double_field_put(offset, orig_mirror->double_field(offset));
879 break;
880 default:
881 ShouldNotReachHere();
882 }
883 nfields ++;
884 }
885 }
886
887 oop class_data = java_lang_Class::class_data(orig_mirror);
888 java_lang_Class::set_class_data(m, class_data);
889 if (class_data != nullptr) {
890 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
891 assert(success, "sanity");
892 }
893
894 if (log_is_enabled(Debug, aot, init)) {
895 ResourceMark rm;
896 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
897 ik->is_hidden() ? " (hidden)" : "",
898 ik->is_enum_subclass() ? " (enum)" : "");
899 }
900 }
901
902 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
903 // We need to retain the identity_hash, because it may have been used by some hashtables
904 // in the shared heap.
905 if (!orig_mirror->fast_no_hash_check()) {
906 intptr_t src_hash = orig_mirror->identity_hash();
907 if (UseCompactObjectHeaders) {
908 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
909 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
910 } else {
911 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
912 }
913 assert(scratch_m->mark().is_unlocked(), "sanity");
914
915 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
916 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
917 }
918
919 if (CDSConfig::is_dumping_aot_linked_classes()) {
920 java_lang_Class::set_module(scratch_m, java_lang_Class::module(orig_mirror));
921 java_lang_Class::set_protection_domain(scratch_m, java_lang_Class::protection_domain(orig_mirror));
922 }
923
924 Klass* k = java_lang_Class::as_Klass(orig_mirror); // is null Universe::void_mirror();
925 if (CDSConfig::is_dumping_reflection_data() &&
926 k != nullptr && k->is_instance_klass() &&
927 java_lang_Class::reflection_data(orig_mirror) != nullptr &&
928 AOTConstantPoolResolver::can_archive_reflection_data(InstanceKlass::cast(k))) {
929 java_lang_Class::set_reflection_data(scratch_m, java_lang_Class::reflection_data(orig_mirror));
930 }
931 }
932
933 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
934 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
935 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
936 if (rr != nullptr && !HeapShared::is_too_large_to_archive(rr)) {
937 return HeapShared::scratch_resolved_references(src_ik->constants());
938 }
939 }
940 return nullptr;
941 }
942
943 int HeapShared::archive_exception_instance(oop exception) {
944 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
945 assert(success, "sanity");
946 return append_root(exception);
947 }
948
949 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
950 OopHandle oh(&src_obj);
951 CachedOopInfo* info = archived_object_cache()->get(oh);
952 assert(info != nullptr, "must be");
953 has_oop_pointers = info->has_oop_pointers();
954 has_native_pointers = info->has_native_pointers();
955 }
956
957 void HeapShared::set_has_native_pointers(oop src_obj) {
958 OopHandle oh(&src_obj);
959 CachedOopInfo* info = archived_object_cache()->get(oh);
960 assert(info != nullptr, "must be");
961 info->set_has_native_pointers();
962 }
963
964 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
965 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
966 void HeapShared::start_scanning_for_oops() {
967 {
968 NoSafepointVerifier nsv;
969
970 // The special subgraph doesn't belong to any class. We use Object_klass() here just
971 // for convenience.
972 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
973 _context = new GrowableArrayCHeap<const char*, mtClassShared>(250);
974
975 // Cache for recording where the archived objects are copied to
976 create_archived_object_cache();
977
978 if (HeapShared::is_writing_mapping_mode() && (UseG1GC || UseCompressedOops)) {
979 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
980 UseCompressedOops ? p2i(CompressedOops::begin()) :
981 p2i((address)G1CollectedHeap::heap()->reserved().start()),
982 UseCompressedOops ? p2i(CompressedOops::end()) :
983 p2i((address)G1CollectedHeap::heap()->reserved().end()));
984 }
985
986 archive_subgraphs();
987 }
988
989 init_seen_objects_table();
990 Universe::archive_exception_instances();
991 }
992
993 void HeapShared::end_scanning_for_oops() {
994 if (is_writing_mapping_mode()) {
995 StringTable::init_shared_table();
996 }
997 delete_seen_objects_table();
998 }
999
1000 void HeapShared::write_heap(ArchiveMappedHeapInfo* mapped_heap_info, ArchiveStreamedHeapInfo* streamed_heap_info) {
1001 {
1002 NoSafepointVerifier nsv;
1003 if (!SkipArchiveHeapVerification) {
1004 CDSHeapVerifier::verify();
1005 }
1006 check_special_subgraph_classes();
1007 }
1008
1009 if (HeapShared::is_writing_mapping_mode()) {
1010 StringTable::write_shared_table();
1011 AOTMappedHeapWriter::write(_pending_roots, mapped_heap_info);
1012 } else {
1013 assert(HeapShared::is_writing_streaming_mode(), "are there more modes?");
1014 AOTStreamedHeapWriter::write(_pending_roots, streamed_heap_info);
1015 }
1016
1017 ArchiveBuilder::OtherROAllocMark mark;
1018 write_subgraph_info_table();
1019
1020 delete _pending_roots;
1021 _pending_roots = nullptr;
1022
1023 make_archived_object_cache_gc_safe();
1024 }
1025
1026 void HeapShared::scan_java_mirror(oop orig_mirror) {
1027 oop m = scratch_java_mirror(orig_mirror);
1028 if (m != nullptr) { // nullptr if for custom class loader
1029 copy_java_mirror(orig_mirror, m);
1030 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
1031 assert(success, "sanity");
1032
1033 oop extra;
1034 if ((extra = java_lang_Class::reflection_data(m)) != nullptr) {
1035 success = archive_reachable_objects_from(1, _dump_time_special_subgraph, extra);
1036 assert(success, "sanity");
1037 }
1038 }
1039 }
1040
1041 void HeapShared::scan_java_class(Klass* orig_k) {
1042 scan_java_mirror(orig_k->java_mirror());
1043
1044 if (orig_k->is_instance_klass()) {
1045 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
1046 orig_ik->constants()->prepare_resolved_references_for_archiving();
1047 objArrayOop rr = get_archived_resolved_references(orig_ik);
1048 if (rr != nullptr) {
1049 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
1050 assert(success, "must be");
1051 }
1052 }
1053 }
1054
1055 void HeapShared::archive_subgraphs() {
1056 assert(CDSConfig::is_dumping_heap(), "must be");
1057
1058 if (CDSConfig::is_dumping_klass_subgraphs()) {
1059 archive_object_subgraphs(archive_subgraph_entry_fields,
1060 false /* is_full_module_graph */);
1061 if (CDSConfig::is_dumping_full_module_graph()) {
1062 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
1063 true /* is_full_module_graph */);
1064 }
1065 }
1066 }
1067
1068 //
1069 // Subgraph archiving support
1070 //
1071 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
1072 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
1073
1074 // Get the subgraph_info for Klass k. A new subgraph_info is created if
1075 // there is no existing one for k. The subgraph_info records the "buffered"
1076 // address of the class.
1077 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
1078 assert(CDSConfig::is_dumping_heap(), "dump time only");
1079 bool created;
1080 KlassSubGraphInfo* info =
1081 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
1082 &created);
1083 assert(created, "must not initialize twice");
1084 return info;
1085 }
1086
1087 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
1088 assert(CDSConfig::is_dumping_heap(), "dump time only");
1089 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
1090 assert(info != nullptr, "must have been initialized");
1091 return info;
1092 }
1093
1094 // Add an entry field to the current KlassSubGraphInfo.
1095 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
1096 assert(CDSConfig::is_dumping_heap(), "dump time only");
1097 if (_subgraph_entry_fields == nullptr) {
1098 _subgraph_entry_fields =
1099 new (mtClass) GrowableArray<int>(10, mtClass);
1100 }
1101 _subgraph_entry_fields->append(static_field_offset);
1102 if (v == nullptr) {
1103 _subgraph_entry_fields->append(-1);
1104 } else {
1105 _subgraph_entry_fields->append(HeapShared::append_root(v));
1106 }
1107 }
1108
1109 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1110 // Only objects of boot classes can be included in sub-graph.
1111 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1112 assert(CDSConfig::is_dumping_heap(), "dump time only");
1113
1114 if (_subgraph_object_klasses == nullptr) {
1115 _subgraph_object_klasses =
1116 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1117 }
1118
1119 if (_k == orig_k) {
1120 // Don't add the Klass containing the sub-graph to it's own klass
1121 // initialization list.
1122 return;
1123 }
1124
1125 if (orig_k->is_instance_klass()) {
1126 #ifdef ASSERT
1127 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1128 if (CDSConfig::is_dumping_method_handles()) {
1129 // -XX:AOTInitTestClass must be used carefully in regression tests to
1130 // include only classes that are safe to aot-initialize.
1131 assert(ik->class_loader() == nullptr ||
1132 HeapShared::is_lambda_proxy_klass(ik) ||
1133 AOTClassInitializer::has_test_class(),
1134 "we can archive only instances of boot classes or lambda proxy classes");
1135 } else {
1136 assert(ik->class_loader() == nullptr, "must be boot class");
1137 }
1138 #endif
1139 // vmClasses::xxx_klass() are not updated, need to check
1140 // the original Klass*
1141 if (orig_k == vmClasses::String_klass() ||
1142 orig_k == vmClasses::Object_klass()) {
1143 // Initialized early during VM initialization. No need to be added
1144 // to the sub-graph object class list.
1145 return;
1146 }
1147 check_allowed_klass(InstanceKlass::cast(orig_k));
1148 } else if (orig_k->is_objArray_klass()) {
1149 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1150 if (abk->is_instance_klass()) {
1151 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1152 "must be boot class");
1153 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1154 }
1155 if (orig_k == Universe::objectArrayKlass()) {
1156 // Initialized early during Universe::genesis. No need to be added
1157 // to the list.
1158 return;
1159 }
1160 } else {
1161 assert(orig_k->is_typeArray_klass(), "must be");
1162 // Primitive type arrays are created early during Universe::genesis.
1163 return;
1164 }
1165
1166 if (log_is_enabled(Debug, aot, heap)) {
1167 if (!_subgraph_object_klasses->contains(orig_k)) {
1168 ResourceMark rm;
1169 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1170 }
1171 }
1172
1173 _subgraph_object_klasses->append_if_missing(orig_k);
1174 _has_non_early_klasses |= is_non_early_klass(orig_k);
1175 }
1176
1177 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1178 #ifndef PRODUCT
1179 if (AOTClassInitializer::has_test_class()) {
1180 // The tests can cache arbitrary types of objects.
1181 return;
1182 }
1183 #endif
1184
1185 if (ik->module()->name() == vmSymbols::java_base()) {
1186 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1187 return;
1188 }
1189
1190 const char* lambda_msg = "";
1191 if (CDSConfig::is_dumping_method_handles()) {
1192 lambda_msg = ", or a lambda proxy class";
1193 if (HeapShared::is_lambda_proxy_klass(ik) &&
1194 (ik->class_loader() == nullptr ||
1195 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1196 ik->class_loader() == SystemDictionary::java_system_loader())) {
1197 return;
1198 }
1199 }
1200
1201 #ifndef PRODUCT
1202 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1203 // This class is loaded by ArchiveHeapTestClass
1204 return;
1205 }
1206 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1207 #else
1208 const char* testcls_msg = "";
1209 #endif
1210
1211 ResourceMark rm;
1212 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1213 ik->external_name(), lambda_msg, testcls_msg);
1214 AOTMetaspace::unrecoverable_writing_error();
1215 }
1216
1217 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1218 if (k->is_objArray_klass()) {
1219 k = ObjArrayKlass::cast(k)->bottom_klass();
1220 }
1221 if (k->is_instance_klass()) {
1222 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1223 ResourceMark rm;
1224 log_info(aot, heap)("non-early: %s", k->external_name());
1225 return true;
1226 } else {
1227 return false;
1228 }
1229 } else {
1230 return false;
1231 }
1232 }
1233
1234 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1235 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1236 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1237 _entry_field_records = nullptr;
1238 _subgraph_object_klasses = nullptr;
1239 _is_full_module_graph = info->is_full_module_graph();
1240
1241 if (_is_full_module_graph) {
1242 // Consider all classes referenced by the full module graph as early -- we will be
1243 // allocating objects of these classes during JVMTI early phase, so they cannot
1244 // be processed by (non-early) JVMTI ClassFileLoadHook
1245 _has_non_early_klasses = false;
1246 } else {
1247 _has_non_early_klasses = info->has_non_early_klasses();
1248 }
1249
1250 if (_has_non_early_klasses) {
1251 ResourceMark rm;
1252 log_info(aot, heap)(
1253 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1254 _k->external_name());
1255 }
1256
1257 // populate the entry fields
1258 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1259 if (entry_fields != nullptr) {
1260 int num_entry_fields = entry_fields->length();
1261 assert(num_entry_fields % 2 == 0, "sanity");
1262 _entry_field_records =
1263 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1264 for (int i = 0 ; i < num_entry_fields; i++) {
1265 _entry_field_records->at_put(i, entry_fields->at(i));
1266 }
1267 }
1268
1269 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1270 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1271 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1272 if (recorded_klasses != nullptr) {
1273 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1274 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1275 // that are not aot-inited.
1276 int num_to_copy = 0;
1277 for (int i = 0; i < recorded_klasses->length(); i++) {
1278 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1279 if (!subgraph_k->has_aot_initialized_mirror()) {
1280 num_to_copy ++;
1281 }
1282 }
1283
1284 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1285 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1286 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1287 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1288 if (subgraph_k->has_aot_initialized_mirror()) {
1289 continue;
1290 }
1291 if (log_is_enabled(Info, aot, heap)) {
1292 ResourceMark rm;
1293 const char* owner_name = is_special ? "<special>" : _k->external_name();
1294 if (subgraph_k->is_instance_klass()) {
1295 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1296 }
1297 log_info(aot, heap)(
1298 "Archived object klass %s (%2d) => %s",
1299 owner_name, n, subgraph_k->external_name());
1300 }
1301 _subgraph_object_klasses->at_put(n, subgraph_k);
1302 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1303 n++;
1304 }
1305 }
1306
1307 ArchivePtrMarker::mark_pointer(&_k);
1308 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1309 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1310 }
1311
1312 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1313 CompactHashtableWriter* _writer;
1314 public:
1315 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1316
1317 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1318 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1319 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1320 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1321 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1322 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1323 _writer->add(hash, delta);
1324 }
1325 return true; // keep on iterating
1326 }
1327 };
1328
1329 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1330 ArchivedKlassSubGraphInfoRecord* record =
1331 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1332 record->init(info);
1333 if (info == _dump_time_special_subgraph) {
1334 _run_time_special_subgraph = record;
1335 }
1336 return record;
1337 }
1338
1339 // Build the records of archived subgraph infos, which include:
1340 // - Entry points to all subgraphs from the containing class mirror. The entry
1341 // points are static fields in the mirror. For each entry point, the field
1342 // offset, and value are recorded in the sub-graph
1343 // info. The value is stored back to the corresponding field at runtime.
1344 // - A list of klasses that need to be loaded/initialized before archived
1345 // java object sub-graph can be accessed at runtime.
1346 void HeapShared::write_subgraph_info_table() {
1347 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1348 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1349 CompactHashtableStats stats;
1350
1351 _run_time_subgraph_info_table.reset();
1352
1353 CompactHashtableWriter writer(d_table->number_of_entries(), &stats);
1354 CopyKlassSubGraphInfoToArchive copy(&writer);
1355 d_table->iterate(©);
1356 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1357
1358 #ifndef PRODUCT
1359 if (ArchiveHeapTestClass != nullptr) {
1360 size_t len = strlen(ArchiveHeapTestClass) + 1;
1361 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1362 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1363 _archived_ArchiveHeapTestClass = array;
1364 }
1365 #endif
1366 if (log_is_enabled(Info, aot, heap)) {
1367 print_stats();
1368 }
1369 }
1370
1371 void HeapShared::serialize_tables(SerializeClosure* soc) {
1372
1373 #ifndef PRODUCT
1374 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1375 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1376 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1377 setup_test_class(_test_class_name);
1378 }
1379 #endif
1380
1381 _run_time_subgraph_info_table.serialize_header(soc);
1382 soc->do_ptr(&_run_time_special_subgraph);
1383 }
1384
1385 static void verify_the_heap(Klass* k, const char* which) {
1386 if (VerifyArchivedFields > 0) {
1387 ResourceMark rm;
1388 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1389 which, k->external_name());
1390
1391 if (VerifyArchivedFields == 1) {
1392 VM_Verify verify_op;
1393 VMThread::execute(&verify_op);
1394 } else if (VerifyArchivedFields == 2 && is_init_completed()) {
1395 // At this time, the oop->klass() of some archived objects in the heap may not
1396 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1397 // have enough information (object size, oop maps, etc) so that a GC can be safely
1398 // performed.
1399 //
1400 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1401 // to check for GC safety.
1402 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1403 which, k->external_name());
1404 FlagSetting fs1(VerifyBeforeGC, true);
1405 FlagSetting fs2(VerifyDuringGC, true);
1406 FlagSetting fs3(VerifyAfterGC, true);
1407 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1408 }
1409 }
1410 }
1411
1412 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1413 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1414 //
1415 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1416 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1417 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1418 void HeapShared::resolve_classes(JavaThread* current) {
1419 assert(CDSConfig::is_using_archive(), "runtime only!");
1420 if (CDSConfig::is_using_klass_subgraphs()) {
1421 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1422 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1423 }
1424 }
1425
1426 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1427 for (int i = 0; fields[i].valid(); i++) {
1428 ArchivableStaticFieldInfo* info = &fields[i];
1429 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1430 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1431 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1432 resolve_classes_for_subgraph_of(current, k);
1433 }
1434 }
1435
1436 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1437 JavaThread* THREAD = current;
1438 ExceptionMark em(THREAD);
1439 const ArchivedKlassSubGraphInfoRecord* record =
1440 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1441 if (HAS_PENDING_EXCEPTION) {
1442 CLEAR_PENDING_EXCEPTION;
1443 }
1444 if (record == nullptr) {
1445 clear_archived_roots_of(k);
1446 }
1447 }
1448
1449 static const char* java_lang_invoke_core_klasses[] = {
1450 "java/lang/invoke/Invokers$Holder",
1451 "java/lang/invoke/MethodHandle",
1452 "java/lang/invoke/MethodHandleNatives",
1453 "java/lang/invoke/DirectMethodHandle$Holder",
1454 "java/lang/invoke/DelegatingMethodHandle$Holder",
1455 "java/lang/invoke/LambdaForm$Holder",
1456 "java/lang/invoke/BoundMethodHandle$Species_L",
1457 };
1458
1459 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1460 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1461 int len = sizeof(java_lang_invoke_core_klasses)/sizeof(char*);
1462 for (int i = 0; i < len; i++) {
1463 resolve_or_init(java_lang_invoke_core_klasses[i], true, CHECK);
1464 }
1465 }
1466 }
1467
1468 bool HeapShared::is_core_java_lang_invoke_klass(InstanceKlass* klass) {
1469 // TODO: Crude, rewrite using Symbols or vmClasses instead
1470 ResourceMark rm;
1471 char* s2 = klass->name()->as_C_string();
1472 int len = sizeof(java_lang_invoke_core_klasses)/sizeof(char*);
1473 for (int i = 0; i < len; i++) {
1474 if (strcmp(java_lang_invoke_core_klasses[i], s2) == 0) {
1475 return true;
1476 }
1477 }
1478 return false;
1479 }
1480
1481 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1482 // - interned strings
1483 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1484 // - ConstantPool::resolved_references()
1485 // - Universe::<xxx>_exception_instance()
1486 //
1487 // For example, if this enum class is initialized at AOT cache assembly time:
1488 //
1489 // enum Fruit {
1490 // APPLE, ORANGE, BANANA;
1491 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1492 // }
1493 //
1494 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1495 // should be initialized before any Java code can access the Fruit class. Note that
1496 // HashSet itself doesn't necessary need to be an aot-initialized class.
1497 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1498 if (!is_archived_heap_in_use()) {
1499 return;
1500 }
1501
1502 assert( _run_time_special_subgraph != nullptr, "must be");
1503 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1504 if (klasses != nullptr) {
1505 for (int pass = 0; pass < 2; pass ++) {
1506 for (int i = 0; i < klasses->length(); i++) {
1507 Klass* k = klasses->at(i);
1508 if (k->class_loader_data() == nullptr) {
1509 // This class is not yet loaded. We will initialize it in a later phase.
1510 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1511 // but k is part of AOTLinkedClassCategory::BOOT2.
1512 continue;
1513 }
1514 if (k->class_loader() == class_loader()) {
1515 if (pass == 0) {
1516 if (k->is_instance_klass()) {
1517 InstanceKlass::cast(k)->link_class(CHECK);
1518 }
1519 } else {
1520 resolve_or_init(k, /*do_init*/true, CHECK);
1521 }
1522 }
1523 }
1524 }
1525 }
1526 }
1527
1528 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1529 JavaThread* THREAD = current;
1530 if (!CDSConfig::is_using_klass_subgraphs()) {
1531 return; // nothing to do
1532 }
1533
1534 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1535 !CDSConfig::is_using_optimized_module_handling() &&
1536 // archive was created with --module-path
1537 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1538 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1539 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1540 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1541 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1542 AOTClassLocationConfig::runtime()->num_module_paths());
1543 return;
1544 }
1545
1546 ExceptionMark em(THREAD);
1547 const ArchivedKlassSubGraphInfoRecord* record =
1548 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1549
1550 if (HAS_PENDING_EXCEPTION) {
1551 CLEAR_PENDING_EXCEPTION;
1552 // None of the field value will be set if there was an exception when initializing the classes.
1553 // The java code will not see any of the archived objects in the
1554 // subgraphs referenced from k in this case.
1555 return;
1556 }
1557
1558 if (record != nullptr) {
1559 init_archived_fields_for(k, record);
1560 }
1561 }
1562
1563 const ArchivedKlassSubGraphInfoRecord*
1564 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1565 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1566
1567 if (!k->in_aot_cache()) {
1568 return nullptr;
1569 }
1570 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1571 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1572
1573 #ifndef PRODUCT
1574 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1575 _test_class = k;
1576 _test_class_record = record;
1577 }
1578 #endif
1579
1580 // Initialize from archived data. Currently this is done only
1581 // during VM initialization time. No lock is needed.
1582 if (record == nullptr) {
1583 if (log_is_enabled(Info, aot, heap)) {
1584 ResourceMark rm(THREAD);
1585 log_info(aot, heap)("subgraph %s is not recorded",
1586 k->external_name());
1587 }
1588 return nullptr;
1589 } else {
1590 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1591 if (log_is_enabled(Info, aot, heap)) {
1592 ResourceMark rm(THREAD);
1593 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1594 k->external_name());
1595 }
1596 return nullptr;
1597 }
1598
1599 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1600 if (log_is_enabled(Info, aot, heap)) {
1601 ResourceMark rm(THREAD);
1602 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1603 k->external_name());
1604 }
1605 return nullptr;
1606 }
1607
1608 if (log_is_enabled(Info, aot, heap)) {
1609 ResourceMark rm;
1610 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1611 }
1612
1613 resolve_or_init(k, do_init, CHECK_NULL);
1614
1615 // Load/link/initialize the klasses of the objects in the subgraph.
1616 // nullptr class loader is used.
1617 Array<Klass*>* klasses = record->subgraph_object_klasses();
1618 if (klasses != nullptr) {
1619 for (int i = 0; i < klasses->length(); i++) {
1620 Klass* klass = klasses->at(i);
1621 if (!klass->in_aot_cache()) {
1622 return nullptr;
1623 }
1624 resolve_or_init(klass, do_init, CHECK_NULL);
1625 }
1626 }
1627 }
1628
1629 return record;
1630 }
1631
1632 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1633 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1634 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1635 if (k == nullptr) {
1636 return;
1637 }
1638 assert(k->defined_by_boot_loader(), "sanity");
1639 resolve_or_init(k, false, CHECK);
1640 if (do_init) {
1641 resolve_or_init(k, true, CHECK);
1642 }
1643 }
1644
1645 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1646 if (!do_init) {
1647 if (k->class_loader_data() == nullptr) {
1648 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1649 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1650 }
1651 } else {
1652 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1653 if (k->is_instance_klass()) {
1654 InstanceKlass* ik = InstanceKlass::cast(k);
1655 ik->initialize(CHECK);
1656 } else if (k->is_objArray_klass()) {
1657 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1658 oak->initialize(CHECK);
1659 }
1660 }
1661 }
1662
1663 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1664 verify_the_heap(k, "before");
1665
1666 Array<int>* entry_field_records = record->entry_field_records();
1667 if (entry_field_records != nullptr) {
1668 int efr_len = entry_field_records->length();
1669 assert(efr_len % 2 == 0, "sanity");
1670 for (int i = 0; i < efr_len; i += 2) {
1671 int field_offset = entry_field_records->at(i);
1672 int root_index = entry_field_records->at(i+1);
1673 // Load the subgraph entry fields from the record and store them back to
1674 // the corresponding fields within the mirror.
1675 oop v;
1676 if (root_index < 0) {
1677 v = nullptr;
1678 } else {
1679 v = get_root(root_index, /*clear=*/true);
1680 }
1681 oop m = k->java_mirror();
1682 if (k->has_aot_initialized_mirror()) {
1683 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1684 } else {
1685 m->obj_field_put(field_offset, v);
1686 }
1687 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1688 }
1689
1690 // Done. Java code can see the archived sub-graphs referenced from k's
1691 // mirror after this point.
1692 if (log_is_enabled(Info, aot, heap)) {
1693 ResourceMark rm;
1694 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1695 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1696 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1697 }
1698 }
1699
1700 verify_the_heap(k, "after ");
1701 }
1702
1703 void HeapShared::clear_archived_roots_of(Klass* k) {
1704 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1705 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1706 if (record != nullptr) {
1707 Array<int>* entry_field_records = record->entry_field_records();
1708 if (entry_field_records != nullptr) {
1709 int efr_len = entry_field_records->length();
1710 assert(efr_len % 2 == 0, "sanity");
1711 for (int i = 0; i < efr_len; i += 2) {
1712 int root_index = entry_field_records->at(i+1);
1713 clear_root(root_index);
1714 }
1715 }
1716 }
1717 }
1718
1719 // Push all oop fields (or oop array elemenets in case of an objArray) in
1720 // _referencing_obj onto the _stack.
1721 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1722 PendingOopStack* _stack;
1723 GrowableArray<oop> _found_oop_fields;
1724 int _level;
1725 bool _record_klasses_only;
1726 KlassSubGraphInfo* _subgraph_info;
1727 oop _referencing_obj;
1728 bool _is_java_lang_ref;
1729 public:
1730 OopFieldPusher(PendingOopStack* stack,
1731 int level,
1732 bool record_klasses_only,
1733 KlassSubGraphInfo* subgraph_info,
1734 oop orig) :
1735 _stack(stack),
1736 _found_oop_fields(),
1737 _level(level),
1738 _record_klasses_only(record_klasses_only),
1739 _subgraph_info(subgraph_info),
1740 _referencing_obj(orig) {
1741 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1742 }
1743 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1744 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1745
1746 ~OopFieldPusher() {
1747 while (_found_oop_fields.length() > 0) {
1748 // This produces the exact same traversal order as the previous version
1749 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1750 // walking the oop fields in _referencing_obj by ascending field offsets.
1751 oop obj = _found_oop_fields.pop();
1752 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1753 }
1754 }
1755
1756 protected:
1757 template <class T> void do_oop_work(T *p) {
1758 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1759 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1760 if (obj != nullptr) {
1761 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1762 // Do not follow these fields. They will be cleared to null.
1763 return;
1764 }
1765
1766 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1767 ResourceMark rm;
1768 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1769 _referencing_obj->klass()->external_name(), field_offset,
1770 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1771 if (log_is_enabled(Trace, aot, heap)) {
1772 LogTarget(Trace, aot, heap) log;
1773 LogStream out(log);
1774 obj->print_on(&out);
1775 }
1776 }
1777
1778 _found_oop_fields.push(obj);
1779 }
1780 }
1781
1782 public:
1783 oop referencing_obj() { return _referencing_obj; }
1784 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1785 };
1786
1787 // Checks if an oop has any non-null oop fields
1788 class PointsToOopsChecker : public BasicOopIterateClosure {
1789 bool _result;
1790
1791 template <class T> void check(T *p) {
1792 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1793 }
1794
1795 public:
1796 PointsToOopsChecker() : _result(false) {}
1797 void do_oop(narrowOop *p) { check(p); }
1798 void do_oop( oop *p) { check(p); }
1799 bool result() { return _result; }
1800 };
1801
1802 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1803 PointsToOopsChecker points_to_oops_checker;
1804 obj->oop_iterate(&points_to_oops_checker);
1805 return CachedOopInfo(OopHandle(Universe::vm_global(), referrer), points_to_oops_checker.result());
1806 }
1807
1808 void HeapShared::init_box_classes(TRAPS) {
1809 if (is_archived_heap_in_use()) {
1810 vmClasses::Boolean_klass()->initialize(CHECK);
1811 vmClasses::Character_klass()->initialize(CHECK);
1812 vmClasses::Float_klass()->initialize(CHECK);
1813 vmClasses::Double_klass()->initialize(CHECK);
1814 vmClasses::Byte_klass()->initialize(CHECK);
1815 vmClasses::Short_klass()->initialize(CHECK);
1816 vmClasses::Integer_klass()->initialize(CHECK);
1817 vmClasses::Long_klass()->initialize(CHECK);
1818 vmClasses::Void_klass()->initialize(CHECK);
1819 }
1820 }
1821
1822 void HeapShared::exit_on_error() {
1823 if (_context != nullptr) {
1824 ResourceMark rm;
1825 LogStream ls(Log(cds, heap)::error());
1826 ls.print_cr("Context");
1827 for (int i = 0; i < _context->length(); i++) {
1828 const char* s = _context->at(i);
1829 ls.print_cr("- %s", s);
1830 }
1831 }
1832 debug_trace();
1833 AOTMetaspace::unrecoverable_writing_error();
1834 }
1835
1836 // (1) If orig_obj has not been archived yet, archive it.
1837 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1838 // trace all objects that are reachable from it, and make sure these objects are archived.
1839 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1840 // were already archived when this function is called)
1841 bool HeapShared::archive_reachable_objects_from(int level,
1842 KlassSubGraphInfo* subgraph_info,
1843 oop orig_obj) {
1844 assert(orig_obj != nullptr, "must be");
1845 PendingOopStack stack;
1846 stack.push(PendingOop(orig_obj, nullptr, level));
1847
1848 while (stack.length() > 0) {
1849 PendingOop po = stack.pop();
1850 _object_being_archived = po;
1851 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1852 _object_being_archived = PendingOop();
1853
1854 if (!status) {
1855 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1856 // as the Java code will take care of initializing this field dynamically.
1857 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1858 return false;
1859 }
1860 }
1861
1862 return true;
1863 }
1864
1865 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1866 oop orig_obj, oop referrer) {
1867 assert(orig_obj != nullptr, "must be");
1868 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1869 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1870 // If you get an error here, you probably made a change in the JDK library that has added
1871 // these objects that are referenced (directly or indirectly) by static fields.
1872 ResourceMark rm;
1873 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1874 debug_trace();
1875 AOTMetaspace::unrecoverable_writing_error();
1876 }
1877
1878 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1879 ResourceMark rm;
1880 LogTarget(Debug, aot, heap) log;
1881 LogStream out(log);
1882 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1883 Klass* k = java_lang_Class::as_Klass(orig_obj);
1884 if (k != nullptr) {
1885 out.print("%s", k->external_name());
1886 } else {
1887 out.print("primitive");
1888 }
1889 out.print_cr("; scratch mirror = " PTR_FORMAT,
1890 p2i(scratch_java_mirror(orig_obj)));
1891 }
1892
1893 if (java_lang_Class::is_instance(orig_obj)) {
1894 Klass* k = java_lang_Class::as_Klass(orig_obj);
1895 if (RegeneratedClasses::has_been_regenerated(k)) {
1896 orig_obj = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
1897 }
1898 }
1899
1900 if (CDSConfig::is_dumping_aot_linked_classes()) {
1901 if (java_lang_Class::is_instance(orig_obj)) {
1902 orig_obj = scratch_java_mirror(orig_obj);
1903 assert(orig_obj != nullptr, "must be archived");
1904 }
1905 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1906 // Without CDSConfig::is_dumping_aot_linked_classes(), we only allow archived objects to
1907 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1908 // very early by HeapShared::init_box_classes().
1909 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1910 || java_lang_Class::is_primitive(orig_obj)
1911 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1912 || orig_obj == vmClasses::Character_klass()->java_mirror()
1913 || orig_obj == vmClasses::Float_klass()->java_mirror()
1914 || orig_obj == vmClasses::Double_klass()->java_mirror()
1915 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1916 || orig_obj == vmClasses::Short_klass()->java_mirror()
1917 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1918 || orig_obj == vmClasses::Long_klass()->java_mirror()
1919 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1920 orig_obj = scratch_java_mirror(orig_obj);
1921 assert(orig_obj != nullptr, "must be archived");
1922 } else {
1923 // If you get an error here, you probably made a change in the JDK library that has added a Class
1924 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1925 // defined at the top of this file.
1926 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1927 debug_trace();
1928 AOTMetaspace::unrecoverable_writing_error();
1929 }
1930 }
1931
1932 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1933 // orig_obj has already been archived and traced. Nothing more to do.
1934 return true;
1935 } else {
1936 set_has_been_seen_during_subgraph_recording(orig_obj);
1937 }
1938
1939 bool already_archived = has_been_archived(orig_obj);
1940 bool record_klasses_only = already_archived;
1941 if (!already_archived) {
1942 ++_num_new_archived_objs;
1943 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1944 // Skip archiving the sub-graph referenced from the current entry field.
1945 ResourceMark rm;
1946 log_error(aot, heap)(
1947 "Cannot archive the sub-graph referenced from %s object ("
1948 PTR_FORMAT ") size %zu, skipped.",
1949 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1950 if (level == 1) {
1951 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1952 // as the Java code will take care of initializing this field dynamically.
1953 return false;
1954 } else {
1955 // We don't know how to handle an object that has been archived, but some of its reachable
1956 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1957 // we have a real use case.
1958 AOTMetaspace::unrecoverable_writing_error();
1959 }
1960 }
1961 }
1962
1963 Klass *orig_k = orig_obj->klass();
1964 subgraph_info->add_subgraph_object_klass(orig_k);
1965
1966 {
1967 // Find all the oops that are referenced by orig_obj, push them onto the stack
1968 // so we can work on them next.
1969 ResourceMark rm;
1970 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1971 orig_obj->oop_iterate(&pusher);
1972 }
1973
1974 if (CDSConfig::is_dumping_aot_linked_classes()) {
1975 // The enum klasses are archived with aot-initialized mirror.
1976 // See AOTClassInitializer::can_archive_initialized_mirror().
1977 } else {
1978 // This is legacy support for enum classes before JEP 483 -- we cannot rerun
1979 // the enum's <clinit> in the production run, so special handling is needed.
1980 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1981 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1982 }
1983 }
1984
1985 return true;
1986 }
1987
1988 //
1989 // Start from the given static field in a java mirror and archive the
1990 // complete sub-graph of java heap objects that are reached directly
1991 // or indirectly from the starting object by following references.
1992 // Sub-graph archiving restrictions (current):
1993 //
1994 // - All classes of objects in the archived sub-graph (including the
1995 // entry class) must be boot class only.
1996 // - No java.lang.Class instance (java mirror) can be included inside
1997 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1998 //
1999 // The Java heap object sub-graph archiving process (see OopFieldPusher):
2000 //
2001 // 1) Java object sub-graph archiving starts from a given static field
2002 // within a Class instance (java mirror). If the static field is a
2003 // reference field and points to a non-null java object, proceed to
2004 // the next step.
2005 //
2006 // 2) Archives the referenced java object. If an archived copy of the
2007 // current object already exists, updates the pointer in the archived
2008 // copy of the referencing object to point to the current archived object.
2009 // Otherwise, proceed to the next step.
2010 //
2011 // 3) Follows all references within the current java object and recursively
2012 // archive the sub-graph of objects starting from each reference.
2013 //
2014 // 4) Updates the pointer in the archived copy of referencing object to
2015 // point to the current archived object.
2016 //
2017 // 5) The Klass of the current java object is added to the list of Klasses
2018 // for loading and initializing before any object in the archived graph can
2019 // be accessed at runtime.
2020 //
2021 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
2022 const char* klass_name,
2023 int field_offset,
2024 const char* field_name) {
2025 precond(CDSConfig::is_dumping_klass_subgraphs());
2026 assert(k->defined_by_boot_loader(), "must be boot class");
2027
2028 oop m = k->java_mirror();
2029
2030 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
2031 oop f = m->obj_field(field_offset);
2032
2033 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
2034
2035 if (!CompressedOops::is_null(f)) {
2036 if (log_is_enabled(Trace, aot, heap)) {
2037 LogTarget(Trace, aot, heap) log;
2038 LogStream out(log);
2039 f->print_on(&out);
2040 }
2041
2042 bool success = archive_reachable_objects_from(1, subgraph_info, f);
2043 if (!success) {
2044 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
2045 klass_name, field_name);
2046 } else {
2047 // Note: the field value is not preserved in the archived mirror.
2048 // Record the field as a new subGraph entry point. The recorded
2049 // information is restored from the archive at runtime.
2050 subgraph_info->add_subgraph_entry_field(field_offset, f);
2051 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
2052 }
2053 } else {
2054 // The field contains null, we still need to record the entry point,
2055 // so it can be restored at runtime.
2056 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
2057 }
2058 }
2059
2060 #ifndef PRODUCT
2061 class VerifySharedOopClosure: public BasicOopIterateClosure {
2062 public:
2063 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
2064 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
2065
2066 protected:
2067 template <class T> void do_oop_work(T *p) {
2068 oop obj = HeapAccess<>::oop_load(p);
2069 if (obj != nullptr) {
2070 HeapShared::verify_reachable_objects_from(obj);
2071 }
2072 }
2073 };
2074
2075 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
2076 precond(CDSConfig::is_dumping_klass_subgraphs());
2077 assert(k->defined_by_boot_loader(), "must be boot class");
2078
2079 oop m = k->java_mirror();
2080 oop f = m->obj_field(field_offset);
2081 if (!CompressedOops::is_null(f)) {
2082 verify_subgraph_from(f);
2083 }
2084 }
2085
2086 void HeapShared::verify_subgraph_from(oop orig_obj) {
2087 if (!has_been_archived(orig_obj)) {
2088 // It's OK for the root of a subgraph to be not archived. See comments in
2089 // archive_reachable_objects_from().
2090 return;
2091 }
2092
2093 // Verify that all objects reachable from orig_obj are archived.
2094 init_seen_objects_table();
2095 verify_reachable_objects_from(orig_obj);
2096 delete_seen_objects_table();
2097 }
2098
2099 void HeapShared::verify_reachable_objects_from(oop obj) {
2100 _num_total_verifications ++;
2101 if (java_lang_Class::is_instance(obj)) {
2102 Klass* k = java_lang_Class::as_Klass(obj);
2103 if (RegeneratedClasses::has_been_regenerated(k)) {
2104 k = RegeneratedClasses::get_regenerated_object(k);
2105 obj = k->java_mirror();
2106 }
2107 obj = scratch_java_mirror(obj);
2108 assert(obj != nullptr, "must be");
2109 }
2110 if (!has_been_seen_during_subgraph_recording(obj)) {
2111 set_has_been_seen_during_subgraph_recording(obj);
2112 assert(has_been_archived(obj), "must be");
2113 VerifySharedOopClosure walker;
2114 obj->oop_iterate(&walker);
2115 }
2116 }
2117 #endif
2118
2119 void HeapShared::check_special_subgraph_classes() {
2120 if (CDSConfig::is_dumping_aot_linked_classes()) {
2121 // We can have aot-initialized classes (such as Enums) that can reference objects
2122 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
2123 // aot-initialize classes that are "safe".
2124 //
2125 // TODO: we need an automatic tool that checks the safety of aot-initialized
2126 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
2127 return;
2128 } else {
2129 // In this case, the special subgraph should contain a few specific types
2130 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
2131 int num = klasses->length();
2132 for (int i = 0; i < num; i++) {
2133 Klass* subgraph_k = klasses->at(i);
2134 Symbol* name = subgraph_k->name();
2135 if (subgraph_k->is_instance_klass() &&
2136 name != vmSymbols::java_lang_Class() &&
2137 name != vmSymbols::java_lang_String() &&
2138 name != vmSymbols::java_lang_ArithmeticException() &&
2139 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
2140 name != vmSymbols::java_lang_ArrayStoreException() &&
2141 name != vmSymbols::java_lang_ClassCastException() &&
2142 name != vmSymbols::java_lang_InternalError() &&
2143 name != vmSymbols::java_lang_NullPointerException() &&
2144 name != vmSymbols::jdk_internal_vm_PreemptedException()) {
2145 ResourceMark rm;
2146 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
2147 }
2148 }
2149 }
2150 }
2151
2152 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2153 HeapShared::PendingOop HeapShared::_object_being_archived;
2154 size_t HeapShared::_num_new_walked_objs;
2155 size_t HeapShared::_num_new_archived_objs;
2156 size_t HeapShared::_num_old_recorded_klasses;
2157
2158 size_t HeapShared::_num_total_subgraph_recordings = 0;
2159 size_t HeapShared::_num_total_walked_objs = 0;
2160 size_t HeapShared::_num_total_archived_objs = 0;
2161 size_t HeapShared::_num_total_recorded_klasses = 0;
2162 size_t HeapShared::_num_total_verifications = 0;
2163
2164 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2165 return _seen_objects_table->get(obj) != nullptr;
2166 }
2167
2168 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2169 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2170 _seen_objects_table->put_when_absent(obj, true);
2171 _seen_objects_table->maybe_grow();
2172 ++ _num_new_walked_objs;
2173 }
2174
2175 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2176 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2177 init_subgraph_info(k, is_full_module_graph);
2178 init_seen_objects_table();
2179 _num_new_walked_objs = 0;
2180 _num_new_archived_objs = 0;
2181 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2182 }
2183
2184 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2185 size_t num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2186 _num_old_recorded_klasses;
2187 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2188 "walked %zu objs, archived %zu new objs, recorded %zu classes",
2189 class_name, _num_new_walked_objs, _num_new_archived_objs,
2190 num_new_recorded_klasses);
2191
2192 delete_seen_objects_table();
2193
2194 _num_total_subgraph_recordings ++;
2195 _num_total_walked_objs += _num_new_walked_objs;
2196 _num_total_archived_objs += _num_new_archived_objs;
2197 _num_total_recorded_klasses += num_new_recorded_klasses;
2198 }
2199
2200 class ArchivableStaticFieldFinder: public FieldClosure {
2201 InstanceKlass* _ik;
2202 Symbol* _field_name;
2203 bool _found;
2204 int _offset;
2205 public:
2206 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2207 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2208
2209 virtual void do_field(fieldDescriptor* fd) {
2210 if (fd->name() == _field_name) {
2211 assert(!_found, "fields can never be overloaded");
2212 if (is_reference_type(fd->field_type())) {
2213 _found = true;
2214 _offset = fd->offset();
2215 }
2216 }
2217 }
2218 bool found() { return _found; }
2219 int offset() { return _offset; }
2220 };
2221
2222 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2223 TRAPS) {
2224 for (int i = 0; fields[i].valid(); i++) {
2225 ArchivableStaticFieldInfo* info = &fields[i];
2226 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2227 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2228 ResourceMark rm; // for stringStream::as_string() etc.
2229
2230 #ifndef PRODUCT
2231 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2232 const char* test_class_name = ArchiveHeapTestClass;
2233 #else
2234 bool is_test_class = false;
2235 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2236 #endif
2237
2238 if (is_test_class) {
2239 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2240 }
2241
2242 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2243 if (HAS_PENDING_EXCEPTION) {
2244 CLEAR_PENDING_EXCEPTION;
2245 stringStream st;
2246 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2247 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2248 }
2249
2250 if (!k->is_instance_klass()) {
2251 stringStream st;
2252 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2253 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2254 }
2255
2256 InstanceKlass* ik = InstanceKlass::cast(k);
2257 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2258 "Only support boot classes");
2259
2260 if (is_test_class) {
2261 if (ik->module()->is_named()) {
2262 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2263 // core-lib classes. You need to at least append to the bootclasspath.
2264 stringStream st;
2265 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2266 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2267 }
2268
2269 if (ik->package() != nullptr) {
2270 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2271 stringStream st;
2272 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2273 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2274 }
2275 } else {
2276 if (ik->module()->name() != vmSymbols::java_base()) {
2277 // We don't want to deal with cases when a module is unavailable at runtime.
2278 // FUTURE -- load from archived heap only when module graph has not changed
2279 // between dump and runtime.
2280 stringStream st;
2281 st.print("%s is not in java.base module", info->klass_name);
2282 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2283 }
2284 }
2285
2286 if (is_test_class) {
2287 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2288 }
2289 ik->initialize(CHECK);
2290
2291 ArchivableStaticFieldFinder finder(ik, field_name);
2292 ik->do_local_static_fields(&finder);
2293 if (!finder.found()) {
2294 stringStream st;
2295 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2296 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2297 }
2298
2299 info->klass = ik;
2300 info->offset = finder.offset();
2301 }
2302 }
2303
2304 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2305 assert(CDSConfig::is_dumping_heap(), "must be");
2306 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2307 if (CDSConfig::is_dumping_klass_subgraphs()) {
2308 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2309 if (CDSConfig::is_dumping_full_module_graph()) {
2310 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2311 }
2312 }
2313 }
2314
2315 #ifndef PRODUCT
2316 void HeapShared::setup_test_class(const char* test_class_name) {
2317 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2318 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2319 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2320 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2321
2322 if (test_class_name != nullptr) {
2323 p[num_slots - 2].klass_name = test_class_name;
2324 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2325 }
2326 }
2327
2328 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2329 // during runtime. This may be called before the module system is initialized so
2330 // we cannot rely on InstanceKlass::module(), etc.
2331 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2332 if (_test_class != nullptr) {
2333 if (ik == _test_class) {
2334 return true;
2335 }
2336 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2337 if (klasses == nullptr) {
2338 return false;
2339 }
2340
2341 for (int i = 0; i < klasses->length(); i++) {
2342 Klass* k = klasses->at(i);
2343 if (k == ik) {
2344 Symbol* name;
2345 if (k->is_instance_klass()) {
2346 name = InstanceKlass::cast(k)->name();
2347 } else if (k->is_objArray_klass()) {
2348 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2349 if (!bk->is_instance_klass()) {
2350 return false;
2351 }
2352 name = bk->name();
2353 } else {
2354 return false;
2355 }
2356
2357 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2358 // to be:
2359 // (A) java.base classes (which must not be in the unnamed module)
2360 // (B) test classes which must be in the unnamed package of the unnamed module.
2361 // So if we see a '/' character in the class name, it must be in (A);
2362 // otherwise it must be in (B).
2363 if (name->index_of_at(0, "/", 1) >= 0) {
2364 return false; // (A)
2365 }
2366
2367 return true; // (B)
2368 }
2369 }
2370 }
2371
2372 return false;
2373 }
2374
2375 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2376 Klass* k = _test_class;
2377 if (k != nullptr && is_archived_heap_in_use()) {
2378 JavaThread* THREAD = current;
2379 ExceptionMark em(THREAD);
2380 const ArchivedKlassSubGraphInfoRecord* record =
2381 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2382
2383 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2384 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2385 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2386 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2387 if (record != nullptr) {
2388 init_archived_fields_for(k, record);
2389 }
2390 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2391 }
2392 }
2393 #endif
2394
2395 void HeapShared::init_for_dumping(TRAPS) {
2396 if (CDSConfig::is_dumping_heap()) {
2397 setup_test_class(ArchiveHeapTestClass);
2398 init_subgraph_entry_fields(CHECK);
2399 }
2400 }
2401
2402 void HeapShared::init_heap_writer() {
2403 if (HeapShared::is_writing_streaming_mode()) {
2404 AOTStreamedHeapWriter::init();
2405 } else {
2406 AOTMappedHeapWriter::init();
2407 }
2408 }
2409
2410 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2411 bool is_full_module_graph) {
2412 _num_total_subgraph_recordings = 0;
2413 _num_total_walked_objs = 0;
2414 _num_total_archived_objs = 0;
2415 _num_total_recorded_klasses = 0;
2416 _num_total_verifications = 0;
2417
2418 // For each class X that has one or more archived fields:
2419 // [1] Dump the subgraph of each archived field
2420 // [2] Create a list of all the class of the objects that can be reached
2421 // by any of these static fields.
2422 // At runtime, these classes are initialized before X's archived fields
2423 // are restored by HeapShared::initialize_from_archived_subgraph().
2424 for (int i = 0; fields[i].valid(); ) {
2425 ArchivableStaticFieldInfo* info = &fields[i];
2426 const char* klass_name = info->klass_name;
2427 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2428
2429 ContextMark cm(klass_name);
2430 // If you have specified consecutive fields of the same klass in
2431 // fields[], these will be archived in the same
2432 // {start_recording_subgraph ... done_recording_subgraph} pass to
2433 // save time.
2434 for (; fields[i].valid(); i++) {
2435 ArchivableStaticFieldInfo* f = &fields[i];
2436 if (f->klass_name != klass_name) {
2437 break;
2438 }
2439
2440 ContextMark cm(f->field_name);
2441 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2442 f->offset, f->field_name);
2443 }
2444 done_recording_subgraph(info->klass, klass_name);
2445 }
2446
2447 log_info(aot, heap)("Archived subgraph records = %zu",
2448 _num_total_subgraph_recordings);
2449 log_info(aot, heap)(" Walked %zu objects", _num_total_walked_objs);
2450 log_info(aot, heap)(" Archived %zu objects", _num_total_archived_objs);
2451 log_info(aot, heap)(" Recorded %zu klasses", _num_total_recorded_klasses);
2452
2453 #ifndef PRODUCT
2454 for (int i = 0; fields[i].valid(); i++) {
2455 ArchivableStaticFieldInfo* f = &fields[i];
2456 verify_subgraph_from_static_field(f->klass, f->offset);
2457 }
2458 log_info(aot, heap)(" Verified %zu references", _num_total_verifications);
2459 #endif
2460 }
2461
2462 bool HeapShared::is_interned_string(oop obj) {
2463 if (!java_lang_String::is_instance(obj)) {
2464 return false;
2465 }
2466
2467 ResourceMark rm;
2468 int len = 0;
2469 jchar* name = java_lang_String::as_unicode_string_or_null(obj, len);
2470 if (name == nullptr) {
2471 fatal("Insufficient memory for dumping");
2472 }
2473 return StringTable::lookup(name, len) == obj;
2474 }
2475
2476 bool HeapShared::is_dumped_interned_string(oop o) {
2477 return is_interned_string(o) && has_been_archived(o);
2478 }
2479
2480 // These tables should be used only within the CDS safepoint, so
2481 // delete them before we exit the safepoint. Otherwise the table will
2482 // contain bad oops after a GC.
2483 void HeapShared::delete_tables_with_raw_oops() {
2484 assert(_seen_objects_table == nullptr, "should have been deleted");
2485
2486 if (is_writing_mapping_mode()) {
2487 AOTMappedHeapWriter::delete_tables_with_raw_oops();
2488 } else {
2489 assert(is_writing_streaming_mode(), "what other mode?");
2490 AOTStreamedHeapWriter::delete_tables_with_raw_oops();
2491 }
2492 }
2493
2494 void HeapShared::debug_trace() {
2495 ResourceMark rm;
2496 oop referrer = _object_being_archived.referrer();
2497 if (referrer != nullptr) {
2498 LogStream ls(Log(aot, heap)::error());
2499 ls.print_cr("Reference trace");
2500 CDSHeapVerifier::trace_to_root(&ls, referrer);
2501 }
2502 }
2503
2504 #ifndef PRODUCT
2505 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2506 // region. This way we can quickly relocate all the pointers without using
2507 // BasicOopIterateClosure at runtime.
2508 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2509 void* _start;
2510 BitMap *_oopmap;
2511 size_t _num_total_oops;
2512 size_t _num_null_oops;
2513 public:
2514 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2515 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2516
2517 virtual void do_oop(narrowOop* p) {
2518 assert(UseCompressedOops, "sanity");
2519 _num_total_oops ++;
2520 narrowOop v = *p;
2521 if (!CompressedOops::is_null(v)) {
2522 size_t idx = p - (narrowOop*)_start;
2523 _oopmap->set_bit(idx);
2524 } else {
2525 _num_null_oops ++;
2526 }
2527 }
2528 virtual void do_oop(oop* p) {
2529 assert(!UseCompressedOops, "sanity");
2530 _num_total_oops ++;
2531 if ((*p) != nullptr) {
2532 size_t idx = p - (oop*)_start;
2533 _oopmap->set_bit(idx);
2534 } else {
2535 _num_null_oops ++;
2536 }
2537 }
2538 size_t num_total_oops() const { return _num_total_oops; }
2539 size_t num_null_oops() const { return _num_null_oops; }
2540 };
2541 #endif
2542
2543 void HeapShared::count_allocation(size_t size) {
2544 _total_obj_count ++;
2545 _total_obj_size += size;
2546 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2547 if (size <= (size_t(1) << i)) {
2548 _alloc_count[i] ++;
2549 _alloc_size[i] += size;
2550 return;
2551 }
2552 }
2553 }
2554
2555 static double avg_size(size_t size, size_t count) {
2556 double avg = 0;
2557 if (count > 0) {
2558 avg = double(size * HeapWordSize) / double(count);
2559 }
2560 return avg;
2561 }
2562
2563 void HeapShared::print_stats() {
2564 size_t huge_count = _total_obj_count;
2565 size_t huge_size = _total_obj_size;
2566
2567 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2568 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2569 size_t count = _alloc_count[i];
2570 size_t size = _alloc_size[i];
2571 log_info(aot, heap)("%8zu objects are <= %-6zu"
2572 " bytes (total %8zu bytes, avg %8.1f bytes)",
2573 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2574 huge_count -= count;
2575 huge_size -= size;
2576 }
2577
2578 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2579 ", avg %8.1f bytes)",
2580 huge_count, huge_size * HeapWordSize,
2581 avg_size(huge_size, huge_count));
2582 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2583 ", avg %8.1f bytes)",
2584 _total_obj_count, _total_obj_size * HeapWordSize,
2585 avg_size(_total_obj_size, _total_obj_count));
2586 }
2587
2588 bool HeapShared::is_metadata_field(oop src_obj, int offset) {
2589 bool result = false;
2590 do_metadata_offsets(src_obj, [&](int metadata_offset) {
2591 if (metadata_offset == offset) {
2592 result = true;
2593 }
2594 });
2595 return result;
2596 }
2597
2598 void HeapShared::remap_dumped_metadata(oop src_obj, address archived_object) {
2599 do_metadata_offsets(src_obj, [&](int offset) {
2600 Metadata** buffered_field_addr = (Metadata**)(archived_object + offset);
2601 Metadata* native_ptr = *buffered_field_addr;
2602
2603 if (native_ptr == nullptr) {
2604 return;
2605 }
2606
2607 if (RegeneratedClasses::has_been_regenerated(native_ptr)) {
2608 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr);
2609 }
2610
2611 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
2612 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
2613 *buffered_field_addr = (Metadata*)requested_native_ptr;
2614 });
2615 }
2616
2617 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2618 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2619 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2620 if (k == nullptr) {
2621 return false;
2622 } else {
2623 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2624 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2625 fieldDescriptor fd;
2626 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2627 oop m = k->java_mirror();
2628 oop f = m->obj_field(fd.offset());
2629 if (CompressedOops::is_null(f)) {
2630 return false;
2631 }
2632 } else {
2633 return false;
2634 }
2635 }
2636 return true;
2637 }
2638
2639 #endif // INCLUDE_CDS_JAVA_HEAP